Primer on Bioproducts - BIOCAP Canada

Biological Sensors for Food and SecurityMillions of Canadians become ill from food poisoning each year,and perhaps hundreds die from bacterial pathogens, such asEscherichia coli and Salmonella. Increasingly, the food processingindustry is looking to biology to provide early warning systemsthat can signal the presence of food pathogens. In general, thesystems work by using the natural protein antibodies producedby living things in response to the toxins (antigens) generated byinvading micro-organisms. The antibodies are arranged in apattern; when the antibody “key” fits the pathogen’s antigen“lock,” the pattern or colour automatically betrays the presence ofthe bacteria. These same techniques are also being developed forearly detection of pollution and for defence against biological andchemical weapons.In some cases, DNA from pathogens and other organisms isincorporated into microscopic detection machines known as“gene chips.” Gene chips combine what is known about thebiology of DNA with nanotechnology and informationtechnology to produce a tiny laboratory slide that automaticallysignals to a computer when the genes are turned “on” or “off.” Aswith the genetic modification of bacteria, gene chips allow forinstantaneous detection of pathogens, toxic chemicals and otherharmful substances.Bacteria Sniff OutLandminesThere are an estimated 60–70million landmines buried in thefields and forests of more than 60countries worldwide. According tothe International Committee of theRed Cross, these mines injure or killapproximately 26,000 civiliansevery year. A few years ago, expertsfound a microscopic ally in theirbattle to rid the world of landmines.The bacterium, Pseudomonasputida, was found to have a naturalsensitivity to trinitrotoluene — thewell-known TNT used in explosives.Through transgenic engineering,scientists have genetically modifiedthe bacterium so that it producesthe same protein that jellyfish useto glow fluorescent green. Thejellyfish protein is stimulated whenthe bacterium detects the presenceof TNT. This modified, explosivesensitivebacterium has alreadybeen shown to be very effective indetecting landmines.PRIMER ON BIOPRODUCTS43